Compounds of general structure I ##STR1## wherein Ar represents an aromatic (substituted or unsubstituted) or heteroaromatic (substituted or unsubstituted) ring system exhibit herbicidal activity against a variety of weed species.
While some of the compounds in this family may be prepared by a conventional, convergent approach via the requisite substituted 2-amino-1,2,4-triazolo[1,5-a]pyrimidine, as described in copending application Ser. No. 574,232 filed Jan. 26, 1984, now abandoned, many analogs cannot be made following this approach. The highly insoluble nature of many of the appropriate substituted 2-amino-1,2,4-triazolo[1,5-a]pyrimidines prohibit their reaction with the less reactive and less stable aromatic sulfonyl chlorides.